Presently accelerating ocean acidification is a potential threat to calcareous plankton that are vital to Earth's carbon cycle. This risk is particularly acute in the Southern Ocean because it is a large natural carbon dioxide sink, and the saturation of calcium carbonate in sea water is at greater risk in colder water. A means to economically increase surveillance of Southern Ocean acidification effects is valuable, particularly in southern winter when natural biological utilization of dissolved carbon dioxide is lowest. In addition to measuring and recording temperature, salinity, acidity, transparency, and phosphorescence of Southern Ocean waters, it will be valuable to continually collect actual samples of plankton at different seasons, times of day, water depths, and locations to discern their physiological response over time to the chemical stress of increasing acidity.
Because the Southern Ocean is the world's most hostile marine environment, deployment of autonomous vessels for the above purpose is economically preferable to manned survey ships. Operation of autonomous vessels for long periods of time in remote locations requires a renewable energy source. Pickens, in U.S. Pat. No. 3,872,819, and Hine et al., in U.S. Pat. No. 8,043,133, describe a surface vessel tethered to a subsurface device that develops horizontal propulsion from wave induced vertical motion. However, this arrangement does not permit deep water collection and is at risk of damage from floating ice. Also, the later invention employs solar power for instrumentation and communication, which is not available at high latitudes during critical winter months.
Here I describe a vessel that can harness subsurface wave energy to provide both propulsion and electrical power for onboard systems. It contains an automated means to collect and preserve plankton. The vessel may alternatively operate at depth and in calm seas by the known means of oceanographic gliders.